php里怎么找不到sqlparameter？？？

搜索了下可以像这样指定MYSQL的参数类型，

$query = sprintf("SELECT * FROM Users where UserName='%s' and Password='%s'", 
                  mysql_real_escape_string($Username), 
                  mysql_real_escape_string($Password)); 
mysql_query($query); 

//-----or 

$db = new mysqli("localhost", "user", "pass", "database"); 
$stmt = $mysqli -> prepare("SELECT priv FROM testUsers WHERE username=? AND password=?"); 
$stmt -> bind_param("ss", $user, $pass); 
$stmt -> execute();

看到一老外像这样写，，这个，看起来怪怪的

<?php
$id = mysql_real_escape_string( $_GET['id'] );
$q = "SELECT * FROM `table` WHERE `id` = $id";
?>

表23-1  bind_param第一个参数字符描述

字符种类	代表的数据类型
I	integer
D	double
S	string
B	blob